Electrolytic degradation systems and methods usable in industrial applications

ABSTRACT

The present disclosure relates to the use of a split and single electrical cells in industrial applications, and particularly in aseptic packaging applications.

FIELD

The present disclosure relates to use of electrical cells usable inindustrial applications, and particularly in aseptic packagingapplications.

BACKGROUND

In the food, beverage and dairy markets, a wide array of shelf stablepackaged liquid and semi-liquid foods exist. Shelf stable foods are foodproducts that have been processed so they can be safely stored and soldunder non-refrigerated conditions in a sealed container while having auseful shelf life. These foods range from canned soups to highlyacidified soda and sport drinks. Various techniques are used to produceshelf stable foods. One such technique is aseptic packaging. In atypical aseptic packaging procedure, a liquid food product is thermallysterilized while the food product packaging is separately chemicallysterilized. The sterile food product and sterile packaging are thenbrought together and sealed under sterile conditions. This results in ashelf stable food product.

Chemical sterilization of the food product packaging is often performedin an aseptic packaging filler. Aseptic packaging fillers use a chemicalsterilant to sterilize the food product packaging. Common asepticfillers include a single-use filler and a re-use or recirculatingfiller. A single use filler uses a stock solution of sterilant. Thefiller deposits the sterilant on the inside and sometimes outside ofpackaging to sterilize it. The sterilant can be heated at the point ofdepositing or it can be pre-heated prior to depositing onto thepackaging. Also, certain running conditions (e.g., temperature, contacttime and concentration) are chosen so that the packaging is renderedcommercially sterile. After being deposited inside of the packaging, thespent sterilant drains from the packaging and is exported by the fillereither to a drain or to other parts of the machine for differenttreatments (such as treating an exterior of the packaging). In asingle-use filler, once the sterilant is used, it is discarded.

A re-use or re-circulating filler contains a sump of sterilant. Thissump is held at a desired temperature so that the sterilant is alsomaintained at a desired temperature. The filler draws sterilant fromthis sump and uses it to sterilize inside and/or outside of the foodpackaging. The sterilant then drains away from the packaging and it iscollected and exported back to the same sump which it originated.

After the packaging is treated by either type of filler, it is rinsedwith microbiologically pure water, filled with a food product andsealed. All of these steps occur under sterile conditions inside of thefiller.

One commonly used chemical sterilant is a peracid solution. In thissolution, peracid exists in equilibrium with its correspondingcarboxylic acid and hydrogen peroxide. The equilibrium shifts to thereactant side or the product side of the chemical equilibrium equationbased on the concentration of reactants or products present in a givensolution.

Normally, a peracid solution is provided to an end-user as anequilibrium concentrate and the end-user dilutes the concentrate to thelevel that is required for microbial treatment of their surface ofinterest. When peracid solutions are used in a re-circulating filler,they are re-circulated back to a sump for extended periods of time. Overtime, the peracid inside the sump slowly degrades or equilibrates backto the carboxylic acid and hydrogen peroxide. As a result, the sumpaccumulates higher levels of hydrogen peroxide and carboxylic acid.Filler operators have specifications set for maximum levels of hydrogenperoxide or carboxylic acid in the sump. When the sump approaches thesemaximum levels, the filler must be shut down, drained and refilled withfresh solution. Other filler operators set up fillers so that they havea certain bleed off rate. Adjusting the bleed off rate modifies theaccumulation rate of peroxide and carboxylic acid in the sump so thatthe filler can be run for an extended length of time.

Additionally, other operators include catalase enzymes in the peracidsolution, in order to reduce hydrogen peroxide in the solution. In suchcases, operators must strictly monitor the hydrogen peroxideconcentration and periodically add the enzymes into the solution whenhydrogen peroxide reaches certain levels. The solution must also beprovided at specific temperatures and within certain pH ranges in orderfor these enzymes to work.

Further, once the package is rinsed, e.g. with pure water, the rinseundesirably accumulates residues from the sterilant and is removed fromthe system.

All of these procedures unnecessarily increase the amount of water,energy, chemistry and complexity required to operate an aseptic filler.It is against this background that the present disclosure has been made.

DEFINITIONS

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

As used herein, the term “split cell” or “electrical split cell” meansan electrolytic cell where an anode and a cathode are separated from oneanother by a salt bridge that allows the flow of current between theanode and cathode but retards wholesale transfer of the bulk liquid fromone side of the cell to the other. Any known salt bridge orsemi-permeable membrane in the art can be used, including ion selectivemembranes, high density fiber meshes, and gels.

As used herein, the term “single cell” or “electrical single cell” meansan electrolytic cell where an anode and a cathode are included in thecell.

The term “anode” refers to any positively charged electrode and the term“cathode” refers to any negatively charged electrode.

All numeric values are herein assumed to be modified by the term“about,” whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may include numbers thatare rounded to the nearest significant figure.

Weight percent, percent by weight, % by weight, wt %, and the like aresynonyms that refer to the concentration of a substance as the weight ofthat substance divided by the weight of the composition and multipliedby 100.

The recitation of numerical ranges by endpoints includes all numberssubsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3,3.80, 4 and 5).

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise. Thus, for example, reference to acomposition containing “a compound” includes a mixture of two or morecompounds. As used in this specification and the appended claims, theterm “or” is generally employed in its sense including “and/or” unlessthe content clearly dictates otherwise.

The use of the terms “antimicrobial” in this application does not meanthat any resulting products are approved for use as an antimicrobialagent.

SUMMARY

First, surprisingly, it has been discovered that use of electricity in asplit cell is particularly effective at selectively degrading hydrogenperoxide in peracid compositions. It has also been discovered that suchan electrolytic degradation process is particularly advantageous whenused in industrial operations, such as aseptic filling operations.

The use of the electricity in a split cell to selectively degradehydrogen peroxide in aseptic filling operations is beneficial becauseperoxide builds in concentration over time as a peracid solution isre-circulated in a filler. This creates two problems. First, at somepoint the peroxide accumulates to a point that it can no longer beeffectively rinsed from the treated bottles or removed via filtration ofrinse water. To overcome these issues, all or a portion of the peracidsolution must be diluted with fresh water and fresh peracid chemistrycreating waste of both water and chemistry. Secondly, an optimization ofmicrobial efficacy can be maintained by keeping a ratio ofperacid:hydrogen peroxide below 5:1. In a re-circulated system this cannot be maintained without some means of selectively degrading hydrogenperoxide. The addition of catalase to the solution has been identifiedas a potential path to remediate the build-up of peroxide over time butit suffers from limited stability that requires that its dosage beclosely monitored and controlled. An electrolytic method of eliminatinghydrogen peroxide is beneficial because it is stable, requires no dosingcontrol, and does not require addition of a second chemistry to mitigatethe negative effects of hydrogen peroxide as outlined above.

Accordingly, this disclosure relates to a method of selectivelydegrading hydrogen peroxide in an antimicrobial composition, comprisingproviding an antimicrobial composition comprising hydrogen peroxide,carboxylic acid, and peracid, providing a split cell in fluidcommunication with the antimicrobial composition in order to degrade thehydrogen peroxide while not degrading the carboxylic acid and theperacid. In some cases, the split cell is used to degrade at least 500pm of the hydrogen peroxide in less than 15 minutes. In other cases, thesplit cell is used to maintain predetermined amounts of the hydrogenperoxide, the carboxylic acid, and the peracid. The predeterminedamounts of the hydrogen peroxide, the carboxylic acid, and the peracidcan be:

from about 0.00001% to about 0.5 wt. % hydrogen peroxide;

from about 0.1% to about 20.0 wt. % of a C₁-C₁₀ carboxylic acid; and

from about 0.1% to about 2.0 wt. % of a C₁-C₁₀ peracid.

In certain embodiments, the split cell comprises a first loop and asecond loop that are in electrical communication with one another usinga salt bridge and a power supply that transmits an electric potentialbetween the first loop and the second loop, wherein the first loopcontains a cathode and the second loop contains an anode and the firstloop contains an antimicrobial composition and the second loop containsa reducing solution, the reducing solution being capable of acceptingelectrons from the antimicrobial composition and capable of transmittingelectrical current through the salt bridge into the first loop. Themethod can further include monitoring the amounts of the hydrogenperoxide, the carboxylic acid and/or the peracid and adjusting theelectric potential in order to maintain predetermined amounts of thehydrogen peroxide, the carboxylic acid, and the peracid. In many cases,the method is part of an aseptic packaging method.

A system for maintaining predetermined amounts of hydrogen peroxide,carboxylic acid, and peracid in an antimicrobial composition is alsoprovided, which includes a split cell comprising a first loop and asecond loop that are in electrical communication with one another usinga salt bridge and a power supply that transmits an electric potentialbetween the first loop and the second loop, wherein the first loopcontains a cathode and the second loop contains an anode and the firstloop contains an antimicrobial composition, the antimicrobial solutioncontaining predetermined amounts of hydrogen peroxide, carboxylic acidand peracid, and wherein the second loop contains a reducing solution,the reducing solution being capable of accepting electrons from theantimicrobial composition and capable of transmitting electrical currentthrough the salt bridge into the first loop. The predetermined amountsof hydrogen peroxide, carboxylic acid, and peracid can be:

from about 0.00001% to about 0.5 wt. % hydrogen peroxide;

from about 0.1% to about 20.0 wt. % of a C₁-C₁₀ carboxylic acid; and

from about 0.1% to about 2.0 wt. % of a C₁-C₁₀ peracid.

Further, in some cases, the carboxylic acid is selected from the groupconsisting of acetic acid, octanoic acid, and mixtures thereof, and theperacid is selected from the group consisting of peracetic acid,peroctanoic acid, and mixtures thereof. The system can further include aregulator that measures amounts of hydrogen peroxide and/or peracid andadjusts the electric potential in order to maintain the predeterminedamounts of hydrogen peroxide, carboxylic acid, and peracid.

A method of disinfecting packages through aseptic packaging is alsoprovided, which includes providing an antimicrobial composition havingdesired components, applying the antimicrobial composition to a surfaceof a food package in an amount sufficient to render a final food productlocated in the food package suitable for distribution and sale undernon-refrigerated storage conditions, providing a split cell in fluidcommunication with the antimicrobial composition, and using the splitcell to maintain predetermined amounts of the desired components in theantimicrobial composition. In certain cases, the desired components arehydrogen peroxide, carboxylic acid, and peracid. The predeterminedamounts of hydrogen peroxide, carboxylic acid, and peracid can be:

from about 0.00001% to about 0.5 wt. % hydrogen peroxide;

from about 0.1% to about 20.0 wt. % of a C₁-C₁₀ carboxylic acid; and

from about 0.1% to about 2.0 wt. % of a C₁-C₁₀ peracid.

Also, the carboxylic acid can be selected from the group consisting ofacetic acid, octanoic acid, and mixtures thereof, and the peracid can beselected from the group consisting of peracetic acid, peroctanoic acid,and mixtures thereof.

An aseptic packaging system is also provided, which includes a sump, asterilizing area, a first line that transfers an antimicrobialcomposition from the sump to the sterilizing area wherein theantimicrobial composition comprises predetermined amounts of desiredcomponents, a second line that transfers the antimicrobial compositionfrom the sterilizing area back to the sump or to a drain, one or moreoptional heaters integrated into the second line and/or the first line,and a split cell integrated into the sump, the first line, the secondline, or the one or more optional heaters, wherein the split cellmaintains the predetermined amounts of desired components in theantimicrobial composition. The desired components can be hydrogenperoxide, carboxylic acid, and peracid. Also, the predetermined amountsof hydrogen peroxide, carboxylic acid, and peracid can be:

from about 0.00001% to about 0.5 wt. % hydrogen peroxide;

from about 0.1% to about 20.0 wt. % of a C₁-C₁₀ carboxylic acid; and

from about 0.1% to about 2.0 wt. % of a C₁-C₁₀ peracid.

Also, the carboxylic acid can be selected from the group consisting ofacetic acid, octanoic acid, and mixtures thereof, and the peracid can beselected from the group consisting of peracetic acid, peroctanoic acid,and mixtures thereof.

The split cell of the aseptic packaging system can include a first loopand a second loop that are in electrical communication with one anotherusing a salt bridge, wherein the first loop contains a cathode and thesecond loop contains an anode, and a power supply that transmits anelectric potential between the first loop and the second loop, whereinthe first loop contains an antimicrobial composition and the second loopcontains a reducing solution, the reducing solution being capable ofaccepting electrons from the antimicrobial composition and capable oftransmitting electrical current through the salt bridge into the firstloop. The aseptic packaging system can further include a regulator thatmeasures amounts of hydrogen peroxide and/or peracid and adjusts theelectric potential in order to maintain the predetermined amounts ofhydrogen peroxide, carboxylic acid, and peracid.

A method of disinfecting packages through aseptic packaging is alsoprovided, which includes forming an antimicrobial composition in a sump,the antimicrobial composition comprising hydrogen peroxide, carboxylicacid, and peracid, transporting the antimicrobial composition from thesump to the package using an aseptic line, applying the composition to asurface of a food package in an amount sufficient to render a final foodproduct located in the food package suitable for distribution and saleunder non-refrigerated storage conditions, integrating a split cell intothe aseptic line, and using the split cell to maintain predeterminedamounts of hydrogen peroxide, carboxylic acid, and peracid in theantimicrobial composition. The method can further include activating thesplit cell in response to a reading from a sensor that senses theamounts of hydrogen peroxide, carboxylic acid, and/or peracid oractivating the split cell in a time-based manner.

Secondly, it has been discovered that the use of electricity in a singlecell is effective at degrading desired components in a solution used inindustrial applications, such as aseptic filling operations. Forexample, a single cell can be used to degrade hydrogen peroxide andperacid in certain solutions. In one embodiment, a method ofnon-selectively degrading hydrogen peroxide and peracid in a solution isprovided, which includes the steps of providing a solution comprisinghydrogen peroxide and peracid and providing a single electrolytic cellin fluid communication with the solution in order to degradepredetermined amounts of the hydrogen peroxide and the peracid. Thesolution can be an industrial solution such as a rinse from asepticpackaging applications or an industrial waste solution.

In another embodiment, a method of disinfecting packages through asepticpackaging is provided, including the steps of providing an antimicrobialcomposition having desired components, applying the antimicrobialcomposition to a surface of a food package in an amount sufficient torender a final food product located in the food package suitable fordistribution and sale under non-refrigerated storage conditions,applying a rinse to the surface of the food package after applying theantimicrobial composition; and using a single cell to degradepredetermined amounts of desired components in the used rinse. In somecases, the antimicrobial composition comprises hydrogen peroxide,carboxylic acid, and peracid and the desired components in the usedrinse include hydrogen peroxide and peracid.

Other embodiments provide for an aseptic packaging system, whichincludes a sterilizing area, a first line that transfers anantimicrobial composition to a sterilizing area, wherein theantimicrobial composition comprises predetermined amounts of desiredcomponents, a second line that transfers the antimicrobial compositionaway from the sterilizing area, a third line that transfers a rinse tothe sterilizing area, a fourth line that transfers used rinse away fromthe sterilizing area; and a single cell integrated into the third lineor fourth line, wherein the single cell degrades predetermined amountsof desired components in the used rinse. In some cases, the desiredcomponents of the antimicrobial composition are hydrogen peroxide,carboxylic acid, and peracid and the desired components of the usedrinse are hydrogen peroxide and peracid.

These and other embodiments will be apparent to those of skill in theart and others in view of the following detailed description of someembodiments. It should be understood, however, that this summary, andthe detailed description illustrate only some examples of variousembodiments, and are not intended to be limiting to the invention asclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic of an exemplary split cell;

FIG. 2 shows a schematic of an exemplary bottling operation;

FIG. 3 shows a schematic of one embodiment of integrating a split cellinto an aseptic packaging operation;

FIG. 4 shows a schematic of an exemplary single cell; and

FIG. 5 shows a schematic of one embodiment of integrating a single cellinto an aseptic packaging operation.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

The present disclosure uses a split cell to selectively degrade desiredcomponents in an antimicrobial composition. In certain embodiments, thesplit cell degrades hydrogen peroxide in a composition includingperacid, carboxylic acid, and hydrogen peroxide. Electricity in a splitcell oxidizes hydrogen peroxide to water and oxygen. The use ofelectricity is desirable because it is easily applied, can be controlledand does not require introduction of a secondary chemistry into are-circulating composition. Inclusion of a second chemical in thisprocess undesirably requires secondary dosage control, handling,monitoring and additional regulatory clearances for potential residuesof the second chemistry.

In certain embodiments, a method is provided that includes the steps of:providing an antimicrobial composition and using an electrical splitcell to reduce the concentration of desired components in thecomposition. The split cell is in fluid communication with theantimicrobial composition in a way that allows the cell to interact withand decompose the desired components.

FIG. 1 illustrates an exemplary split cell. The split cell 10 includes afirst loop 1 containing an anode 3 and a second loop 2 containing acathode 4. The first loop 1 and the second loop 2 are in electricalcommunication via a salt bridge 6. A power supply 5 is connected to eachthe anode 3 and cathode 4 and transmits an electrical potential betweenthe first loop 1 and the second loop 2. The first loop 1 contains anantimicrobial composition having predetermined amounts of certaindesired components. The second loop 2 contains a reduction solution thataccepts electrons and donates protons to the antimicrobial compositionacross the salt bridge 6. This solution can be a salt, acid, or base insome embodiments. In certain cases, the solution contains an alkalineearth salt of a carboxylic acid in the peracid solution (e.g., sodium orpotassium acetate or octanoate).

The split cell can be used in any industrial application where it isdesirable to selectively degrade certain desired components. Suchapplications include healthcare, food and beverage, warewashing,laundry, waste water treatment and housekeeping applications. Forexample, in the healthcare field, the split cell may be used toselectively degrade components used to sterilize medical instruments andequipment like surgical instruments and endoscopes. In the food andbeverage field, the split cell may be used to selectively degradecomponents used to sterilize equipment, for example, clean-in-placeequipment such as that found in a dairy, or shipping tanks. Inwarewashing and laundry applications, the split cell may be used toselectively degrade components used during a cycle of use such as awarewashing detergent, sanitizer, or rinse aid, or laundry detergent,sanitizer, bleach, or softener. In the wastewater treatment area, thesplit cell may be used to selectively degrade components used to treatwastewater or may be used to selectively degrade the wastewater itselfas part of a method of treatment.

In some embodiments, the split cell is used to selectively degradehydrogen peroxide in an antimicrobial composition. The antimicrobialcomposition can include hydrogen peroxide, carboxylic acid, and peracid.Any known carboxylic acid and peracid can be used and are discussed infurther detail below. In some cases, the carboxylic acid is selectedfrom the group consisting of acetic acid, octanoic acid, and mixturesthereof, and the peracid is selected from the group consisting ofperacetic acid, peroctanoic acid, and mixtures there.

The split cell is provided in fluid communication with the antimicrobialcomposition in order to degrade the hydrogen peroxide while notdegrading the carboxylic acid and the peracid. The split cell can beadjusted to degrade the hydrogen peroxide at any desired rate, forexample to degrade 500 ppm of hydrogen peroxide in less than 15 minutes.The split cell can also be used to maintained predetermined amounts ofthe hydrogen peroxide, the carboxylic acid, and the peracid. In somecases, the predetermined amounts are:

from about 0.00001% to about 0.5 wt. % hydrogen peroxide;

from about 0.1% to about 20.0 wt. % of a C₁-C₁₀ carboxylic acid; and

from about 0.1% to about 2.0 wt. % of a C₁-C₁₀ peracid.

In some cases, a regulator is provided that monitors and regulates theamounts of hydrogen peroxide, carboxylic acid, and peracid in order tomaintain these predetermined amounts. The regulator can performregulation functions in any desired way. In some cases, the regulatoradjusts the electric potential in response to obtaining a certainmeasurement of the amount of hydrogen peroxide, carboxylic acid, andperacid. In other cases, the regulator adjusts the electric potential ina time-based manner.

In certain embodiments, the split cell is used in an aseptic packagingoperation. Accordingly, a method of disinfecting packages using asepticpackaging is provided that includes providing an antimicrobialcomposition having desired components, applying the antimicrobialcomposition to a surface of the package in an amount that renders thefinal food product located in the food package suitable for distributionand sale under non-refrigerated storage conditions, providing a splitcell in fluid communication with the antimicrobial composition, andusing the split cell to maintain predetermined amounts of the desiredcomponents in the antimicrobial composition. Again, the desiredcomponents can be hydrogen peroxide, carboxylic acid, and peracid, asdiscussed above.

In certain cases, an aseptic packaging system is provided. FIG. 2 showsa schematic for an embodiment of an aseptic packaging system. FIG. 2shows a plant 100 that can contact any desired container with anantimicrobial composition for a sanitizing regime. In FIG. 2, containers110 are passed through a sterilizing tunnel 102. The sanitizedcontainers 110 a then pass through a rinsing tunnel 103 and emerge assanitized rinsed containers 110 b.

Examples of containers that can be treated include polyethyleneterephthalate (PET), high density polyethylene (HDPE), polypropylene(PP), low density polyethylene, polycarbonate (PC), poly vinyl alcohol(PVA), aluminum, single or multilayer films or pouches, paperboard,steel, glass, multilayer bottles, other polymeric packaging material,combinations of these materials in films, pouches, bottles, or otherfood packaging materials.

In the process, the antimicrobial composition is added to a holding tankor sump 101. The composition can be maintained at a desired temperaturein the sump 101. The composition can be transported via an aseptic line112 and passed through a heater 108 to reach a desired temperature. Theheated composition is then pumped to the sterilizing tunnel 102 andsprayed into and onto all surfaces of the containers 110. Thecomposition can be pumped from sump 101 to the container surfaces at adesired rate.

The contact between the containers and the antimicrobial composition canbe at a temperature of greater than about 0° C., greater than 25° C., orgreater than about 40° C. Temperatures between about 40° C. and 90° C.can be used. In certain embodiments, contact at 40° C. to 60° C. for atleast 5 sec, or at least about 10 sec, is employed.

The sanitized containers 110 a are then drained of excess compositionand then passed to a fresh water rinse tunnel 103. Fresh water 108 isprovided from a fresh water make-up into the tunnel 103. The fresh watercan also include a rinse additive. Within the tunnel 103, sanitizedcontainers 110 a are thoroughly rinsed with fresh water. The rinsed andsanitized containers 110 b are then removed from the rinsing tunnel.Excess water drains from the tunnel via drain 106.

The sump 101, sterilizing tunnel 102 and rinsing tunnel 103 are allrespectively vented to a wet scrubber or vent 111 a, 111 b or 111 c toremove vapor or fumes from the system components. The antimicrobialcomposition that has been sprayed and drained from the containers 110 aaccumulate in the bottom of the spray tunnel 102 and is then (a)recycled through recycle line 114 and heater 107 into the sump 101, (b)moved out of the system to the drain, or (c) exported to another part ofthe plant.

FIG. 3 illustrates a split cell 10 that is integrated with the plant 100of FIG. 2. In FIG. 3, the split cell 10 is integrated with the asepticline 112 of the plant 100. However, skilled artisans will understandthat the cell 10 can instead be integrated with other parts of the plant100, such as with the recycle line 114, the heaters 107, 108, or thesump 101. Likewise, the plant 100 can be of any desired design need notinclude only one split cell 10 and any number of split cells can beintegrated with various parts of plant 100.

In the integrated split cell 10 in FIG. 3, the first loop 1 is in fluidcommunication with the aseptic line 112. Antimicrobial composition inthe aseptic line 112 moves through loop 1. As the composition movesthrough loop 1, it loses electrons through application of current by thepower supply (not shown). The current transfers these electrons to loop2 of the cell where they reduce the salt/acid solution residing on theother side of the salt bridge 6. As this happens, certain desiredcomponents are degraded from the composition, so that predeterminedamounts of other desired components are maintained and returned to theaseptic line 112.

At the same time, a reducing solution is present in a reservoir 118 andmoves through the second loop 2 via a line 116. As the reducing solutionmoves through loop 2, it accepts electrons. The flow of current betweenloop 1 and loop 2 is facilitated by the membrane/salt bridge interfacebetween loop 1 and 2. The reducing solution then returns to thereservoir 118 or is otherwise drained from the system. In someembodiments, the reducing solution is a single-use solution that doesnot recirculate. In other embodiments, the reducing solution is arecirculating solution. Replacement/replenishment of the reducingsolution may be controlled automatically through inclusion of anoverflow/bleed-off device whereby a portion of the reducing solution iscontinuously replenished with a fresh solution. It can be manually orautomatically changed based on a timing mechanism linked to a dump andfill mechanism or it can be controlled externally by a pH, conductivity,or other suitable sensor.

A variety of peracid antimicrobial compositions can be used in thepresent methods. In certain cases, the composition includes hydrogenperoxide, carboxylic acid and peracid. Each of these components will bediscussed in detail below.

Hydrogen Peroxide

The antimicrobial composition includes hydrogen peroxide. Hydrogenperoxide, H₂O₂, provides the advantages of having a high ratio of activeoxygen because of its low molecular weight (34.014 g/mole) and beingcompatible with numerous substances that can be treated by the presentmethods because it is a weakly acidic, clear, and colorless liquid.

Another advantage of hydrogen peroxide is that it decomposes into waterand oxygen. These decomposition products are advantageous because theyare generally compatible with substances being treated. For example, thedecomposition products are generally compatible with metallic substances(e.g., substantially noncorrosive) and with food products (e.g., doesnot substantially alter the color, flavor, or nutritional value of afood product). And the decomposition products are generally innocuous toincidental contact with humans and are environmentally friendly.

The composition preferably includes hydrogen peroxide in an amounteffective for maintaining the equilibrium between a carboxylic acid,hydrogen peroxide, and a peracid. The amount of hydrogen peroxide shouldnot exceed an amount that would adversely affect the antimicrobialactivity of the composition. The composition preferably containshydrogen peroxide at a minimal concentration.

Hydrogen peroxide can typically be present in a use solution in anamount of up to about 2500 ppm, preferably between about 3 ppm and about1850 ppm, and more preferably between about 6 ppm and about 1250 ppm.

Carboxylic Acid

The peracid antimicrobial composition of the disclosure also includes acarboxylic acid. A carboxylic acid includes any compound of the formulaR—(COOH)n in which R can be hydrogen, alkyl, alkenyl, alicyclic group,aryl, heteroaryl, or heterocylic group, and n is 1, 2, or 3. PreferablyR includes hydrogen, alkyl, or alkenyl.

The term “alkyl” includes a straight or branched saturated aliphatichydrocarbon chain having from 1 to 12 carbon atoms, such as, forexample, methyl, ethyl, propyl, isopropyl (1-methylethyl), butyl,tert-butyl (1,1-dimethylethyl), and the like.

The term “alkenyl” includes an unsaturated aliphatic hydrocarbon chainhaving from 2 to 12 carbon atoms, such as, for example, ethenyl,1-propenyl, 2-propenyl, 1-butenyl, 2-methyl-1-propenyl, and the like.

The above alkyl or alkenyl can be terminally substituted with aheteroatom, such as, for example, a nitrogen, sulfur, or oxygen atom,forming an aminoalkyl, oxyalkyl, or thioalkyl, for example, aminomethyl,thioethyl, oxypropyl, and the like. Similarly, the above alkyl oralkenyl can be interrupted in the chain by a heteroatom forming analkylaminoalkyl, alkylthioalkyl, or alkoxyalkyl, for example,methylaminoethyl, ethylthiopropyl, methoxymethyl, and the like.

The term “alicyclic” includes any cyclic hydrocarbyl containing from 3to 8 carbon atoms. Examples of suitable alicyclic groups includecyclopropanyl, cyclobutanyl, cyclopentanyl, etc.

The term “heterocyclic” includes any cyclic hydrocarbyl containing from3 to 8 carbon atoms that is interrupted by a heteroatom, such as, forexample, a nitrogen, sulfur, or oxygen atom. Examples of suitableheterocyclic groups include groups derived form tetrahydrofurans,furans, thiophenes, pyrrolidines, piperidines, pyridines, pyrrols,picoline, coumaline, etc.

Alkyl, alkenyl, alicyclic groups, and heterocyclic groups can beunsubstituted or substituted by, for example, aryl, heteroaryl, C₁₋₄alkyl, C₁₋₄ alkenyl, C₁₋₄ alkoxy, amino, carboxy, halo, nitro, cyano,—SO₃H, phosphono, or hydroxy. When alkyl, alkenyl, alicyclic group, orheterocyclic group is substituted, preferably the substitution is C₁₋₄alkyl, halo, nitro, amido, hydroxy, carboxy, sulpho, or phosphono. Inone embodiment, R includes alkyl substituted with hydroxy.

The term “aryl” includes aromatic hydrocarbyl, including fused aromaticrings, such as, for example, phenyl and naphthyl.

The term “heteroaryl” includes heterocyclic aromatic derivatives havingat least one heteroatom such as, for example, nitrogen, oxygen,phosphorus, or sulfur, and includes, for example, furyl, pyrrolyl,thienyl, oxazolyl, pyridyl, imidazolyl, thiazolyl, isoxazolyl,pyrazolyl, isothiazolyl, etc.

The term “heteroaryl” also includes fused rings in which at least onering is aromatic, such as, for example, indolyl, purinyl, benzofuryl,etc.

Aryl and heteroaryl groups can be unsubstituted or substituted on thering by, for example, aryl, heteroaryl, alkyl, alkenyl, alkoxy, amino,carboxy, halo, nitro, cyano, —SO₃H, phosphono, or hydroxy. When aryl,aralkyl, or heteroaryl is substituted, preferably the substitution isC₁₋₄ alkyl, halo, nitro, amido, hydroxy, carboxy, sulpho, or phosphono.In one embodiment, R includes aryl substituted with C₁₋₄ alkyl.

Examples of suitable carboxylic acids include a variety monocarboxylicacids, dicarboxylic acids, and tricarboxylic acids.

Monocarboxylic acids include, for example, formic acid, acetic acid,propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoicacid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid,dodecanoic acid, glycolic acid, lactic acid, salicylic acid,acetylsalicylic acid, mandelic acid, etc.

Dicarboxylic acids include, for example, adipic acid, fumaric acid,glutaric acid, maleic acid, succinic acid, malic acid, tartaric acid,etc.

Tricarboxylic acids include, for example, citric acid, trimellitic acid,isocitric acid, agaicic acid, etc.

A carboxylic acid suitable for use in the composition can be selectedfor its solubility, cost, approval as food additive, odor, purity, etc.

A particularly useful carboxylic acid includes a carboxylic acid that iswater soluble such as formic acid, acetic acid, propionic acid, butanoicacid, lactic acid, glycolic acid, citric acid, mandelic acid, glutaricacid, maleic acid, malic acid, adipic acid, succinic acid, tartaricacid, etc. These carboxylic acids can also be useful becausewater-soluble carboxylic acids can be food additives such as formicacid, acetic acid, lactic acid, citric acid, tartaric acid, etc.

Preferably the composition includes acetic acid, octanoic acid, orpropionic acid, lactic acid, heptanoic acid, or nonanoic acid.

The composition can include a carboxylic acid in an amount that can beeffectively removed from the inside and outside of a package in anaseptic filler during the rinsing step of the aseptic packaging process.A carboxylic acid can typically be present in a use solution in anamount less than 40000 ppm, preferably less than 30000 ppm and morepreferably less than 20000 ppm.

Peracid

The composition also includes a peracid. A peracid is also known in theart as a percarboxylic acid, a peroxyacid, and a peroxycarboxylic acid.

A peracid includes any compound of the formula R—(COOOH)_(n) in which Rcan be hydrogen, alkyl, alkenyl, alicyclic group, aryl, heteroaryl, orheterocyclic group, and n is 1, 2, or 3. Preferably R includes hydrogen,alkyl, or alkenyl.

The terms “alkyl,” “alkenyl,” “alicyclic group,” “aryl,” “heteroaryl,”and “heterocyclic group” are as defined above.

Peracids used in the composition include any peroxycarboxylic acid thatcan be prepared from the acid-catalyzed equilibrium reaction between acarboxylic acid described above and hydrogen peroxide described above.Preferably, the composition includes peroxyacetic acid, peroxyoctanoicacid, or peroxypropionic acid, peroxylactic acid, peroxyheptanoic acid,peroxyoctanoic acid, or peroxynonanoic acid.

A peroxycarboxylic acid can also be prepared by the auto-oxidation ofaldehydes or by the reaction of hydrogen peroxide with an acid chloride,acid hydride, carboxylic acid anhydride, or sodium alcoholate.

In some embodiments, a peroxycarboxylic acid includes at least onewater-soluble peroxycarboxylic acid in which R includes alkyl of 1-4carbon atoms. For example, in one embodiment, a peroxycarboxylic acidincludes peroxyacetic acid. In another embodiment, a peroxycarboxylicacid has R that is an alkyl of 1-4 carbon atoms substituted withhydroxy.

Methods of preparing peroxyacetic acid are known to those of skill inthe art including those disclosed in U.S. Pat. No. 2,833,813, which isincorporated herein by reference.

One advantage of using a peroxycarboxylic acid in which R includes alkylof 1-4 carbon atoms is that such peroxycarboxylic acids traditionallyhave a lower pKa than peroxycarboxylic acids having R that is alkyl withmore than 4 carbon atoms. This lower pKa can favor a faster rate ofperoxycarboxylic acid equilibrium and can be effective for providing acomposition of the disclosure with, for example, acidic pH, which can beadvantageous for improved lime-scale and/or soil removal.

In other embodiments, a peroxycarboxylic acid includes at least oneperoxycarboxylic acid of limited water solubility in which R includesalkyl of 5-12 carbon atoms and at least one water-solubleperoxycarboxylic acid in which R includes alkyl of 1-4 carbon atoms. Forexample, in one embodiment, a peroxycarboxylic acid includesperoxyacetic acid and at least one other peroxycarboxylic acid such asthose named above. Preferably, the composition includes peroxyaceticacid and peroxyoctanoic acid.

One advantage of combining a water-soluble carboxylic acid orperoxycarboxylic acid with a carboxylic acid or peroxycarboxylic acidhaving limited water solubility is that the water-soluble carboxylicacid or peroxycarboxylic acid can provide a hydrotropic effect upon lesswater soluble carboxylic and peroxycarboxylic acids, which canfacilitate uniform dispersion and/or consequent physical stabilitywithin the composition.

Another advantage of this combination of peroxycarboxylic acids is thatit can provide a composition of the disclosure with desirableantimicrobial activity in the presence of high organic soil loads.

The composition can include a peroxycarboxylic acid, or mixturesthereof, in an amount effective for the sterilization of bacterial andfungal spores of public health and spoilage significance on the insideand outside surfaces of a food package in an aseptic filler as well aswithin the enclosure of the filler itself. A peroxycarboxylic acid cantypically be present in this composition in an amount of between about500 ppm and about 6000 ppm, preferably between about 1000 ppm and 5000ppm, and more preferably between about 1500 ppm and about 4000 ppm.

Additional Optional Materials

The composition can optionally include additional ingredients to enhancethe composition including stabilizing agents, hydrotropes, surfactants,defoamers, corrosion inhibitors, rheology modifiers, dyes, andfragrances.

Stabilizing Agents

The composition can optionally include stabilizing agents to stabilizethe peracid and hydrogen peroxide and prevent the premature oxidation ofthis constituent within the composition.

Chelating agents or sequestrants generally useful as stabilizing agentsin the present compositions include phosphonic acid and phosphonates,phosphates, aminocarboxylates and their derivatives, pyrophosphates,ethylenediamine and ethylenetriamine derivatives, hydroxyacids, andmono-, di-, and tri-carboxylates and their corresponding acids. Otherchelating agents include nitroloacetates and their derivatives, andmixtures thereof. Examples of aminocarboxylates include amino acetatesand salts thereof. Suitable amino acetates include:N-hydroxyethylaminodiacetic acid; hydroxyethylenediaminetetraaceticacid; nitrilotriacetic acid (NTA); ethylenediaminetetraacetic acid(EDTA); N-hydroxyethyl-ethylenediaminetriacetic acid (HEDTA);tetrasodium ethylenediaminetetraacetic acid (EDTA);diethylenetriaminepentaacetic acid (DTPA); Na₂EDG, ethanoldiglycine,methylglycinediacetic acid (MGDA), salts of L-glutamic acid N,N-diaceticacid (GLDA), N,N-bis(carboxylatomethyl)-L-glutamate; EDDS,[S—S]-ethylenediaminedisuccinic acid; and3-hydroxy-2,2′-iminodisuccinate, alanine-N,N-diacetic acid;n-hydroxyethyliminodiacetic acid; and the like; their alkali metalsalts; and mixtures thereof. Suitable aminophosphates includenitrilotrismethylene phosphates and other aminophosphates with alkyl oralkaline groups with less than 8 carbon atoms. Exemplarypolycarboxylates iminodisuccinic acids (IDS), sodium polyacrylates,citric acid, gluconic acid, oxalic acid, salts thereof, mixturesthereof, and the like. Additional polycarboxylates include citric orcitrate-type chelating agents, polymeric polycarboxylate, and acrylic orpolyacrylic acid-type chelating agents. Additional chelating agentsinclude polyaspartic acid or co-condensates of aspartic acid with otheramino acids, C₄-C₂₅-mono-or-dicarboxylic acids andC₄-C₂₅-mono-or-diamines. Exemplary polymeric polycarboxylates includepolyacrylic acid, maleic/olefin copolymer, acrylic/maleic copolymer,polymethacrylic acid, acrylic acid-methacrylic acid copolymers,hydrolyzed polyacrylamide, hydrolyzed polymethacrylamide, hydrolyzedpolyamide-methacrylamide copolymers, hydrolyzed polyacrylonitrile,hydrolyzed polymethacrylonitrile, hydrolyzedacrylonitrile-methacrylonitrile copolymers, and the like.

The chelating agent can be present in an amount from about 0.01 to about5 wt. %, from about 0.05 to about 3 wt. %, and from about 0.1 to about1.5 wt. %.

Hydrotropes

The composition can optionally include a hydrotrope coupler orsolubilizer. Such materials can be used to ensure that the compositionremains phase stable and in a single highly active aqueous form. Suchhydrotrope solubilizers or couplers can be used at concentrations thatmaintain phase stability but do not result in unwanted compositionalinteraction.

Representative classes of hydrotrope solubilizers or coupling agentsinclude an anionic surfactant such as an alkyl sulfate, an alkyl oralkane sulfonate, a linear alkyl benzene or naphthalene sulfonate, asecondary alkane sulfonate, alkyl ether sulfate or sulfonate, an alkylphosphate or phosphonate, dialkyl sulfosuccinic acid ester, sugar esters(e.g., sorbitan esters) and a C₈₋₁₀ alkyl glucoside.

Coupling agents can also include n-octane sulfonate, aromatic sulfonatessuch as an alkyl aryl sulfonate (e.g., sodium xylene sulfonate ornaphthalene sulfonate), and alkylated diphenyl oxide disulfonic acids,such as those sold under the DOWFAX™ trade name, preferably the acidforms of these hydrotropes.

The concentration of hydrotrope useful in the present disclosuregenerally ranges from about 0.1 to about 20 wt-%, preferably from about2 to about 18 wt-%, most preferably from about 3 to about 15 wt-%.

Surfactants

The composition can optionally include a surfactant or mixture ofsurfactants. The surfactant may include anionic, nonionic, cationic, andzwitterionic surfactants, which are commercially available, and mixturesthereof. In an embodiment, the surfactant includes a nonionic or anionicsurfactant. For a discussion of surfactants, see Kirk-Othmer,Encyclopedia of Chemical Technology, Third Edition, volume 8, pages900-912.

Nonionic surfactants can include those having a polyalkylene oxidepolymer as a portion of the surfactant molecule. These surfactants canbe capped or uncapped. Such nonionic surfactants include, for example,chlorine-, benzyl-, methyl-, ethyl-, propyl-, butyl-and other likealkyl-capped polyethylene glycol ethers of fatty alcohols; polyalkyleneoxide free nonionics such as alkyl polyglycosides; sorbitan and sucroseesters and their ethoxylates; alkoxylated ethylene diamine; alcoholalkoxylates such as alcohol ethoxylate propoxylates, alcoholpropoxylates, alcohol propoxylate ethoxylate propoxylates, alcoholethoxylate butoxylates, fatty alcohol ethoxylates (e.g., tridecylalcohol alkoxylate, ethylene oxide adduct), and the like; nonylphenolethoxylate, polyoxyethylene glycol ethers, and the like; carboxylic acidesters such as glycerol esters, polyoxyethylene esters, ethoxylated andglycol esters of fatty acids, and the like; carboxylic amides such asdiethanolamine condensates, monoalkanolamine condensates,polyoxyethylene fatty acid amides, and the like; and polyalkylene oxideblock copolymers including an ethylene oxide/propylene oxide blockcopolymer such as those commercially available under the trademarkPLURONIC (BASF-Wyandotte), and the like; ethoxylated amines and etheramines commercially available from Tomah Corporation and other likenonionic compounds. Silicone surfactants such as the ABIL B8852(Goldschmidt) can also be used.

The nonionic surfactant can include linear and secondary alcoholethoxylates (fatty alcohol ethoxylates, e.g., tridecyl alcoholalkoxylate, ethylene oxide adduct), alkyl phenol ethoxylates,ethoxy/propoxy block surfactants, and the like. Examples of preferredlinear and secondary alcohol ethoxylates (fatty alcohol ethoxylates,e.g., tridecyl alcohol alkoxylate, ethylene oxide adduct) include fivemole ethoxylate of linear, primary 12-14 carbon number alcohol(C₁₂₋₁₄H₂₅₋₂₉)—O—(CH₂CH₂O)₅H (one of which is sold under the tradenameLAE 24-5), seven mole ethoxylate of linear, primary 12-14 carbon numberalcohol (C₁₂₋₁₄H₂₅₋₂₉)—O—(CH₂CH₂O)₇H (one of which is sold under thetradename LAE 24-7), twelve mole ethoxylate of linear, primary 12-14carbon number alcohol (C₁₂₋₁₄H₂₅₋₂₉)—O—(CH₂CH₂O)₁₂H (one of which issold under the tradename LAE 24-12), and the like.

Anionic surfactants can include, for example, carboxylates such asalkylcarboxylates (carboxylic acid salts) and polyalkoxycarboxylates,alcohol ethoxylate carboxylates, nonylphenol ethoxylate carboxylates,and the like; sulfonates such as alkylsulfonates, alkylbenzenesulfonates(e.g., linear dodecyl benzene sulfonic acid or salts thereof),alkylarylsulfonates, sulfonated fatty acid esters, and the like;sulfates such as sulfated alcohols, sulfated alcohol ethoxylates,sulfated alkylphenols, alkylsulfates, sulfosuccinates, alkylethersulfates, and the like; and phosphate esters such as alkylphosphateesters, ethoxylated alcohol phosphate esters, and the like. Preferredanionics include sodium alkylarylsulfonate, alkylbenzenesulfonates(e.g., linear dodecyl benzene sulfonic acid or salts thereof), and thelike.

Surface active substances are classified as cationic if the charge onthe hydrophilic portion of the molecule is positive. Surfactants inwhich the hydrophile carries no charge unless the pH is lowered close toneutrality or lower, but which are then cationic (e.g. alkyl amines),are also included in this group.

Cationic surfactants can include compounds containing at least one longcarbon chain hydrophobic group and at least one positively chargednitrogen. The long carbon chain group may be attached directly to thenitrogen atom by simple substitution; or indirectly by a bridgingfunctional group or groups in so-called interrupted alkylamines andamido amines. Such functional groups can make the molecule morehydrophilic and/or more water dispersible, more easily water solubilizedby co-surfactant mixtures, and/or water soluble. For increased watersolubility, additional primary, secondary or tertiary amino groups canbe introduced or the amino nitrogen can be quaternized with lowmolecular weight alkyl groups. Further, the nitrogen can be a part of abranched or straight chain moiety of varying degrees of unsaturation orof a saturated or unsaturated heterocyclic ring. In addition, cationicsurfactants may contain complex linkages having more than one cationicnitrogen atom.

The cationic surfactant can include a quaternary ammonium surfactant,such as tallow quaternary ammonium surfactant, such as a tallow amineethoxylate quaternary ammonium compound. For example, a tallow amineethoxylate quaternary ammonium compound can include a quaternarynitrogen bonded to a methyl group, a tallow moiety, and two ethoxylatemoieties. The ethoxylate moieties can include 6-10 ethoxylate groups. Inan embodiment, the present composition can include about 1 to about 10wt-% or about 5 wt-% of such a cationic surfactant.

The surfactant compounds classified as amine oxides, amphoterics andzwitterions are themselves typically cationic in near neutral to acidicpH solutions and can overlap surfactant classifications.Polyoxyethylated cationic surfactants generally behave like nonionicsurfactants in alkaline solution and like cationic surfactants in acidicsolution.

The majority of large volume commercial cationic surfactants can besubdivided into four major classes and additional sub-groups, forexample, as described in “Surfactant Encyclopedia”, Cosmetics &Toiletries, Vol. 104 (2) 86-96 (1989). The first class includesalkylamines and their salts. The second class includes alkylimidazolines. The third class includes ethoxylated amines. The fourthclass includes quaternaries, such as alkylbenzyldimethylammonium salts,alkyl benzene salts, heterocyclic ammonium salts, dialkylammonium salts,and the like. Cationic surfactants are known to have a variety ofproperties that can be beneficial in the present compositions. Thesedesirable properties can include detergency, antimicrobial efficacy, andthe like.

Defoamers

The composition can optionally include defoamers. Generally, defoamerscan include silica and silicones; aliphatic acids or esters; alcohols;sulfates or sulfonates; amines or amides; halogenated compounds such asfluorochlorohydrocarbons; vegetable oils, waxes, mineral oils as well astheir sulfated derivatives; and phosphates and phosphate esters such asalkyl and alkaline diphosphates, and tributyl phosphates among others;and mixtures thereof.

Food grade defoamers are preferred. To this end, one of the moreeffective antifoaming agents includes silicones. Silicones such asdimethyl silicone, glycol polysiloxane, methylphenol polysiloxane,trialkyl or tetralkyl silanes, hydrophobic silica defoamers and mixturesthereof can all be used in defoaming applications. Commercial defoamerscommonly available include silicones such as Ardefoam® from ArmourIndustrial Chemical Company which is a silicone bound in an organicemulsion; Foam Kill® or Kresseo® available from Krusable ChemicalCompany which are silicone and non-silicone type defoamers as well assilicone esters; and Anti-Foam A® and DC-200 from Dow CorningCorporation which are both food grade type silicones among others. Thesedefoamers can be present at a concentration range from about 0.01 wt-%to 5 wt-%, preferably from about 0.01 wt-% to 2 wt-%, and mostpreferably from about 0.01 wt-% to about 1 wt-%.

Corrosion Inhibitors

The composition can optionally include a corrosion inhibitor. Usefulcorrosion inhibitors include polycarboxylic acids such as short chaincarboxylic diacids, triacids, as well as phosphate esters andcombinations thereof. Useful phosphate esters include alkyl phosphateesters, monoalkyl aryl phosphate esters, dialkyl aryl phosphate esters,trialkyl aryl phosphate esters, and mixtures thereof such as Emphos PS236 commercially available from Witco Chemical Company. Other usefulcorrosion inhibitors include the triazoles, such as benzotriazole,tolyltriazole and mercaptobenzothiazole, and in combinations withphosphonates such as 1-hydroxyethylidene-1,1-diphosphonic acid, andsurfactants such as oleic acid diethanolamide and sodiumcocoamphohydroxy propyl sulfonate, and the like. Useful corrosioninhibitors include polycarboxylic acids such as dicarboxylic acids. Theacids which are preferred include adipic, glutaric, succinic, andmixtures thereof. The most preferred is a mixture of adipic, glutaricand succinic acid, which is a raw material sold by BASF under the nameSOKALAN® DCS.

Rheology Modifiers

The composition can optionally include one or more rheology modifiers.Water soluble or water dispersible rheology modifiers that are usefulcan be classified as inorganic or organic. The organic thickeners canfurther be divided into natural and synthetic polymers with the latterstill further subdivided into synthetic natural-based and syntheticpetroleum-based.

Inorganic thickeners are generally compounds such as colloidal magnesiumaluminum silicate (VEEGUM®), colloidal clays (Bentonites), or silicas(CAB-O-SILS®) which have been fumed or precipitated to create particleswith large surface to size ratios. Suitable natural hydrogel thickenersare primarily vegetable derived exudates. For example, tragacanth,karaya, and acacia gums; and extractives such as carrageenan, locustbean gum, guar gum and pectin; or, pure culture fermentation productssuch as xanthan gum. Chemically, all of these materials are salts ofcomplex anionic polysaccharides. Synthetic natural-based thickenershaving application are cellulose derivatives wherein the free hydroxylgroups on the linear anhydro-glucose polymers have been etherified oresterified to give a family of substances, which dissolve in water andgive viscous solutions. This group of materials includes the alkyl andhydroxyllalkycelluloses, specifically methylcellulose,hydroxyethylmethylcellulose, hydroxypropylmethylcellulose,hydroxybutylmethycellulose, hydroxyethylcellulose,ethylhydroxyethylcellulose, hydroxypropylcellulose, andcarboxymethylcellulose. Synthetic petroleum-based water soluble polymersare prepared by direct polymerization of suitable monomers of whichpolyvinylpyrrolidone, polyvinylmethylether, polyacrylic acid andpolymethacrylic acid, polyacrylamide, polyethylene oxide, andpolyethyleneimine are representative.

Dyes and Fragrances

The composition can optionally include various dyes, odorants includingperfumes, and other aesthetic enhancing agents. Preferred dyes includeFD&C dyes, D&C dyes, and the like.

Examples of containers that can be filled include polyethyleneterephthalate (PET), high density polyethylene (HDPE), polypropylene(PP), low density polyethylene, polycarbonate (PC), poly vinyl alcohol(PVA), aluminum, single or multilayer films or pouches, paperboard,steel, glass, multilayer bottles, other polymeric packaging material,combinations of these materials in films, pouches, bottle, or other foodpackaging materials.

The present disclosure also uses a single cell to degrade desiredcomponents in a solution. FIG. 4 illustrates an exemplary single cell.The single cell 20 includes an anode 3 and a cathode 4 in the same cell.The anode 3 and cathode 4 are both connected to a power supply 5. Thissingle cell 20 can be used in an industrial application to degradecertain components in a solution. For example, in aseptic packagingoperations, the single cell 20 can be provided in fluid communicationwith a rinse, in order to degrade certain components of the rinse. Insome cases, an antimicrobial composition comprising hydrogen peroxide,carboxylic acid, and peracid is used to sterilize food packages and arinse accumulates hydrogen peroxide and peracid during rinsing. Here,the single cell 20 can be used to degrade predetermined amounts of thehydrogen peroxide and peracid in the rinse.

FIG. 5 illustrates a single cell 20 that is integrated with the plant100 of FIG. 2. In FIG. 5, the single cell 20 is integrated with thedrain 106 of the plant 100. However, skilled artisans will understandthat the cell 20 can instead be integrated with other parts of the plant100. Likewise, the plant 100 can be of any desired design and need notinclude only one single cell 20.

In the integrated single cell of FIG. 5, the cell is in fluidcommunication with the drain 106. Rinse solution in the drain 106 movesthrough the cell 20. As this happens, certain desired components aredegraded from the rinse and continue thereon through the drain 106,where it is either recycled back to the plant 100 or removed from theplant 100.

For a more complete understanding of the disclosure, the followingexamples are given to illustrate some embodiments. These examples andexperiments are to be understood as illustrative and not limiting.

EXAMPLES Example 1 Single Cell Experiment

Example 1 examined the ability of a single chamber electrical cell toselectively decompose hydrogen peroxide in the presence of peroxyaceticacid (“POAA”). For this example, two 1″×3″×0.25″ electrically conductivegraphite electrodes were suspended in a single beaker containing asolution of POAA made up from a sample of a 15% POAA equilibriumconcentrate. The beaker was placed on a stirplate and the electrodeswere connected by wire to a variable output power supply. The testfixture was held at room temperature for the duration of the test.

A voltage of 12 VDC at a current of 0.08 A was applied to the solutionand the concentration of hydrogen peroxide and POAA was measured bytitration at zero, one and six hours. The concentration of each wasmeasured via titration of a 10 ml aliquot of the test solution dilutedin ˜100 ml of ice water. POAA concentration is measured by iodometrictitration which entails addition of 1-2 ml of 10.0% KI solution alongwith 2-3 drops of starch indicator followed by titration with 0.1Nsodium thiosulfate to a colorless endpoint. Peroxide content is measuredby addition of 1-2 ml concentrated sulfuric acid and 4-5 drops of anoxygen catalyst (saturated solution of ammonium molybdate) to the samesolution followed by titration with 0.1N sodium thiosulfate to the finalcolorless endpoint.

POAA concentration is calculated via the following calculation:

${{ppm}\mspace{14mu} {POAA}} = \frac{\left( {{ml}\mspace{14mu} {Na}_{2}S_{2}O_{3}} \right)\left( {{Normality}\mspace{14mu} {of}\mspace{14mu} {titrant}} \right)\left( {{Equivalent}\mspace{14mu} {wt}\mspace{14mu} {POAA}} \right)}{\left( {{sample}\mspace{14mu} {size}} \right)(2)}$${{ppm}\mspace{14mu} {POAA}} = \frac{\left( {{ml}\mspace{14mu} {Na}_{2}S_{2}O_{3}} \right)(0.1)(76)}{\left( {10\mspace{14mu} g} \right)(2)}$

Peroxide concentration is calculated via the following calculation:

${{ppm}\mspace{14mu} H_{2}O_{2}} = \frac{\left( {{ml}\mspace{14mu} {Na}_{2}S_{2}O_{3}} \right)\left( {{Normality}\mspace{14mu} {of}\mspace{14mu} {titrant}} \right)\left( {{Equivalent}\mspace{14mu} {wt}\mspace{14mu} H_{2}O_{2}} \right)}{\left( {{sample}\mspace{14mu} {size}} \right)(2)}$${{ppm}\mspace{14mu} {POAA}\mspace{14mu} {or}\mspace{14mu} H_{2}O_{2}} = \frac{\left( {{ml}\mspace{14mu} {Na}_{2}S_{2}O_{3}} \right)(0.1)(34)}{\left( {10\mspace{14mu} g} \right)(2)}$

The concentrations of hydrogen peroxide and POAA are shown in Table 1.

TABLE 1 POAA Concentration (ppm) and Hydrogen Peroxide Concentration(ppm) Over Time (hours). Time (Hours) POAA titration H₂O₂ titration 05.05 ml/1919 ppm 14.75 ml/1649 ppm 1 5.05 ml/1919 ppm  14.6 ml/1623 ppm6  4.0 ml/1520 ppm 12.45 ml/1436 ppm

Table 1 shows that there is little selectivity in degradation of POAAand hydrogen peroxide in this experiment. This is likely due to the factthat both an oxidizing and reducing potential is present in the solutionsince both anode and cathode are in the same beaker. Thus, Table 1 showsthat the single cell did not selectively degrade hydrogen peroxide.However, a single cell is indeed beneficial in degrading both hydrogenperoxide and POAA.

Example 2 Split Cell Experiment

Example 2 compared the ability of a split electrical cell to decomposehydrogen peroxide selectively in the presence of POAA. This experimentwas similar to the experiment in Example 1 with the exception that theanode and cathode were separated into two separate beakers.

One liter of a POAA/hydrogen peroxide solution was split evenly betweenthe two beakers. The two beakers were then connected by a salt bridge.The salt bridge was made by making a 1.0N solution of sodium nitrate andsolidifying that solution with 1.0% agar. This mixture was poured into a½ inch plastic tube while still hot where it solidified. One end of thistube was placed in the beaker containing the anode while the other endwas placed in the beaker containing the cathode forming a salt bridgebetween the 2 beakers/cells.

The power source was again the 1″×3″×0.25″ electrically conductivegraphite electrodes connected to a variable power supply. A voltage of22 VDC at a current of 0.04 A was applied to the solution and the levelof POAA and hydrogen peroxide were measured by titration at the anode(positive connection) and at the cathode (negative connection) atseveral time points to determine the impact of the electrical potentialon the stability of both POAA and hydrogen peroxide. The concentrationof the POAA and the hydrogen peroxide was measured at time zero and atfive hours in the same manner as outlined in Example 1. Theconcentrations of both POAA and hydrogen peroxide are shown in Table 2.Also, control samples are shown, which are samples of a POAA solution towhich no electrical potential was applied.

TABLE 2 POAA Concentration and Hydrogen Peroxide Concentration (ppm)Over Time (hours). POAA/ H₂O₂ POAA/ H₂O₂/ POAA/ H₂O₂/ Time (Hours)Cathode Cathode Anode Anode Control Control 0  7.85 ml  22.8 ml  7.85 ml 22.8 ml 7.85  22.8 ml 2983 ppm 2541 ppm 2983 ppm 2541 ppm 2983 ppm 2541ppm 5  3.90 ml  18.2 ml  7.55 ml  19.4 ml   7.7 ml  23.3 ml 1482 ppm2431 ppm 2869 ppm 2014 ppm 2926 ppm 2652 ppm % change −50% −4.3% −3.8%−20.7% −1.6% +4.36%

Comparison of the peracid and peroxide concentrations in the anodeversus the cathode cells shown in Table 2 shows that the split cell wasable to selectively degrade hydrogen peroxide in the presence of POAA atthe anode with virtually no impact on the stability of the POAAconcentration. Table 2 also shows the necessity of separating the anodereaction from the cathode reaction to achieve the intended technicaleffect and selectively degrade peroxide. Table 1 shows that when theanode and cathode are placed in the same cell, they degrade smalleramounts of both hydrogen peroxide and peracid. But, when the anode andcathode are split with a salt bridge between the two cells, the cathodeside selectively degrades the peracid compared to the peroxide, and theanode side selectively degrades the peroxide compared to the peracid.Thus, a split cell is required for selective electrochemical degradationof peroxide in the presence of peracid. And, the anode portion of thesplit cell should preferably be in direct fluid communication with theperacid/peroxide solution so that it can selectively degrade theperoxide, whereas the cathode portion of the cell will be in electricalcommunication with the peracid solution through the salt bridge, but isotherwise kept separate from the peracid solution so that it will notreduce the solution.

The foregoing summary, detailed description, and examples provide asound basis for understanding the disclosure, and some specific exampleembodiments of the disclosure. Since the invention can comprise avariety of embodiments, the above information is not intended to belimiting. The invention resides in the claims.

We claim:
 1. A method of selectively degrading hydrogen peroxide in anantimicrobial composition, comprising: (a) providing an antimicrobialcomposition comprising hydrogen peroxide, carboxylic acid, and peracid;(b) providing a split cell in fluid communication with the antimicrobialcomposition.
 2. The method of claim 1, comprising using the split cellto degrade at least 500 ppm of the hydrogen peroxide in less than 15minutes.
 3. The method of claim 1, comprising using the split cell tomaintain predetermined amounts of the hydrogen peroxide, the carboxylicacid, and the peracid.
 4. The method of claim 3, wherein thepredetermined amounts of the hydrogen peroxide, the carboxylic acid, andthe peracid are: (i) from about 0.00001 to about 0.5 wt. % hydrogenperoxide; (ii) from about 0.1 to about 20.0 wt. % of a C₁-C₁₀ carboxylicacid; and (iii) from about 0.1 to about 2.0 wt. % of a C₁-C₁₀ peracid.5. The method of claim 1, the split cell comprising a first loop and asecond loop that are in electrical communication with one another usinga salt bridge, wherein the first loop contains an anode and the secondloop contains a cathode connected to a power supply that transmits anelectrical potential between the first loop and the second loop; whereinthe first loop contains the antimicrobial composition and the secondloop contains a reducing solution capable of accepting electrons fromthe antimicrobial composition.
 6. The method of claim 5, furthercomprising monitoring the amounts of the hydrogen peroxide, thecarboxylic acid or the peracid and adjusting the electric potential inorder to maintain predetermined amounts of the hydrogen peroxide, thecarboxylic acid, and the peracid.
 7. The method of claim 1, wherein themethod is part of an aseptic packaging method.
 8. The method of claim 6,wherein the electric potential is adjusted by a regulator.
 9. A systemfor maintaining predetermined amounts of hydrogen peroxide, carboxylicacid, and peracid in an antimicrobial composition, comprising: a splitcell comprising a first loop and a second loop that are in electricalcommunication with one another using a salt bridge, wherein the firstloop contains an anode and the second loop contains a cathode; a powersupply that transmits an electric potential between the first loop andthe second loop; wherein the first loop contains an antimicrobialcomposition, the antimicrobial solution containing predetermined amountsof hydrogen peroxide, carboxylic acid and peracid; and wherein thesecond loop contains a reducing solution, the reducing solution beingcapable of accepting electrons from the antimicrobial solution andcapable of transmitting electrical current through the salt bridge intothe first loop.
 10. The system of claim 9, wherein the predeterminedamounts of hydrogen peroxide, carboxylic acid, and peracid are: (i) fromabout 0.00001 to about 0.5 wt. % hydrogen peroxide; (ii) from about 0.1to about 20.0 wt. % of a C₁-C₁₀ carboxylic acid; and (iii) from about0.1 to about 2.0 wt. % of a C₁-C₁₀ peracid.
 11. The system of claim 9,wherein the carboxylic acid is selected from the group consisting ofacetic acid, octanoic acid, and mixtures thereof, and the peracid isselected from the group consisting of peracetic acid, peroctanoic acid,and mixtures thereof.
 12. The system of claim 9, further comprising aregulator that measures amounts of hydrogen peroxide or peracid andadjusts the electric potential in order to maintain the predeterminedamounts of hydrogen peroxide, carboxylic acid, and peracid.
 13. Anaseptic packaging system, comprising: a sump; a sterilizing area; afirst line that transfers an antimicrobial composition from the sump tothe sterilizing area, wherein the antimicrobial composition comprisespredetermined amounts of desired components; a second line thattransfers the antimicrobial composition from the sterilizing area backto the sump or to a drain; a split cell integrated into the sump, thefirst line, or the second line, wherein the split cell maintains thepredetermined amounts of desired components in the antimicrobialcomposition; a third line that transfers a rinse to the sterilizingarea; a fourth line that transfers used rinse away from the sterilizingarea; and a single cell integrated into the fourth line, wherein thesingle cell degrades predetermined amounts of desired components in theused rinse.
 14. The aseptic packaging system of claim 13, wherein thedesired components of the antimicrobial composition are hydrogenperoxide, carboxylic acid, and peracid and the desired components of theused rinse are hydrogen peroxide and peracid.
 15. A method ofdisinfecting packages through an aseptic or extended shelf life fillingsystem comprising: (a) forming an antimicrobial composition in a sump,the antimicrobial composition comprising: (i) hydrogen peroxide; (ii)carboxylic acid; and (iii) peracid; (b) transporting the antimicrobialcomposition from the sump to the package using an aseptic line; (c)applying the composition to a surface of a food package on a packagingline in an amount sufficient to render a final food product located inthe food package suitable for distribution and sale undernon-refrigerated storage conditions; (d) integrating a split cell intothe packaging line; and (e) using the split cell to maintainpredetermined amounts of hydrogen peroxide, carboxylic acid, and peracidin the antimicrobial composition.
 16. The method of claim 15, whereinthe split cell comprises a first loop and a second loop that are influid communication with one another using a salt bridge, wherein thefirst loop contains an anode and the second loop contains a cathode; anda power supply that transmits an electric potential between the firstloop and the second loop; wherein the first loop contains theantimicrobial composition and the second loop contains a reducingsolution is in fluid communication with the second loop, the reducingsolution being capable of accepting electrons from the antimicrobialcomposition and capable of transmitting electrical current through thesalt bridge into the first loop.
 17. The method of claim 15, furthercomprising activating the split cell in response to a reading from asensor that senses the amounts of hydrogen peroxide, carboxylic acid orperacid.
 18. The method of claim 15, further comprising activating thesplit cell in a time-based manner.
 19. The method of claim 15, whereinthe predetermined amounts of hydrogen peroxide, carboxylic acid, andperacid are: (i) from about 0.00001% to about 0.5 wt. % hydrogenperoxide; (ii) from about 0.1% to about 20.0 wt. % of a C₁-C₁₀carboxylic acid; and (iii) from about 0.1% to about 2.0 wt. % of aC₁-C₁₀ peracid.
 20. The method of claim 15, wherein the carboxylic acidis selected from the group consisting of acetic acid, octanoic acid, andmixtures thereof, and the peracid is selected from the group consistingof peracetic acid, peroctanoic acid, and mixtures thereof.